Recalc of this.
Planet diametre: 909 px, 12 742 000 m
The portion of Earth that is on-screen: 110 px, or 1 541 936.19 m
Panel height: 281 px
Some people on this wiki, when angsizing, go straight for degrees while others get radians first. Guess I'll do both.
2atan(110/(909/tan(70/2))) = 9.686615291124 degrees
If we get radians first...
2atan(110/(909/tan(70/2))) = 0.114549210236 radians
0.114549210236*180/pi = 6.5631862930795685 degrees
Then I use the Angular Size Calculator to get distance:
Low-end Distance: 9 098 700 m (if we go straight for degrees)
High-end Distance: 13 446 000 m (if we get radians first)
10 seconds is probably a reasonable assumption.
9 098 700/10 = 909 870 m/s, Mach 2673.81
13 446 000/10 = 1 344 600 m/s, Mach 3921.95
Either way Massively Hypersonic+